ios - Swift iOS AVSampleBufferDisplayLayer 设置视频层

Question

我正在尝试在基于 Swift 的项目中设置视频流查看器。

我查看了以下非常有帮助的内容( objective-c ):How AVSampleBufferDisplayLayer displays H.264

在 Swift 上下文中，我很难理解 CMTimebaseCreateWithMasterClock 要求 CMTimebase 相关元素的类型为 UnsafeMutablePointer。有人能够解释如何转换为这个并返回以解决以下代码部分中的问题。

var controlTimebase : CMTimebase

var myAllocator : CFAllocator!

CMTimebaseCreateWithMasterClock( myAllocator, CMClockGetHostTimeClock(), CMTimebase) 

// Problem is here...below is the expected format. 

//CMTimebaseCreateWithMasterClock(allocator: CFAllocator!, masterClock: CMClock!, timebaseOut: UnsafeMutablePointer < Unmanaged < CMTimebase > ? >)

videoLayer.controlTimebase = controlTimebase 

Answer 1

在这里发现不同上下文中需要的 UnsafeMutablePointer 语法: CVPixelBufferPool Error ( kCVReturnInvalidArgument/-6661)

使用下面的代码似乎可以愉快地编译 :-)

            var _CMTimebasePointer = UnsafeMutablePointer<Unmanaged<CMTimebase>?>.alloc(1)
        CMTimebaseCreateWithMasterClock( kCFAllocatorDefault, CMClockGetHostTimeClock(),  _CMTimebasePointer )
        videoLayer.controlTimebase = _CMTimebasePointer.memory?.takeUnretainedValue()